Development of tolerance to benzodiazepines. II. Baclofen effect on the activity of rats during tolerance to the sedative action of nitrazepam and oxazepam.

It was demonstrated that baclofen, a GABA-ergic agent, exerted a sedative effect in rats with tolerance to the sedative action of oxazepam and nitrazepam induced by administration of these drugs during several weeks. After one dose baclofen alone reduced the motor activity of rats without potentiating the effects of benzodiazepines. During long-term administration of baclofen tolerance developed also to its sedative action.